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Biomedical subjects

S Behar

Publications and source records attributed to S Behar.

At least 163 records · Page 9Linked to original sources
PubMed1983

A novel cell surface antigen (T305) found in increased frequency on acute leukemia cells and in autoimmune disease states.

Monoclonal antibody T305, prepared by immunizing mice with the T-ALL derived cell line RPMI-8402, immunoprecipitates a single chain glycoprotein with m.w. 160,000 daltons (under reducing conditions) or 180,000 daltons (under nonreducing conditions). In immunofluorescence assays, antibody T305 reacted with a subpopulation of T cells in normal blood (22 +/- 6%), thymus (28 +/- 11%), and lymph node (24 +/- 6%). Increased frequency of T cells reactive with antibody T305 was found in peripheral blood of patients with infectious mononucleosis (greater than 80%), graft-vs-host disease after bone marrow transplantation (65 +/- 11%), acquired immunodeficiency syndrome (53 +/- 12%). The T cells in synovial fluid of patients with rheumatoid arthritis had increased frequency of antibody T305 reactive cells (59 +/- 8%) as compared to their peripheral blood (18 +/- 7%). Two color immunofluorescent studies demonstrated that the T305+ T cells predominantly co-stained with antibody Leu 2a (suppressor/cytotoxic subset) in both normals and disease state blood. After cell sorting to obtain T305+ and T305- subpopulations, we demonstrated that a) natural killer and antibody-dependent cellular cytotoxicity activity in normal blood was in the T305+ but not T305- T cells; b) cytotoxic T cells induced by mixed lymphocyte reaction were predominantly T305+; c) T305- T cells could be induced in vitro to express T305 antigen by mitogens or allogeneic B cells; d) the DNA content of T305+ and T305- T cells in normal blood was similar (greater 95% of cells with G0/G1 level); e) after mitogen stimulation, T305 antigen induction on previously T305- cells occurs before S-phase; and f) significantly more [3H]-thymidine after mitogen stimulation was incorporated by originally T305- cells than by originally T305+ cells (p less than 0.001). The T305 antigen was not restricted to T cells because it was also found on myeloid precursors in bone marrow but was not present on polymorphonuclear leukocytes, red blood cells, platelets, muscle, liver, skin, kidney, lung, or brain. Antibody T305 was found on 24/25 cases of acute leukemia (6 T-ALL, 10/11 cALL, 7 AML, and 1 AMOL) but not on 18 cases of chronic leukemia (B-CLL, T-CLL, null CLL, CML). The importance of the T305 antigen is that it is present on a high number of T cells in certain autoimmune diseases and on virtually all acute leukemia cells. Its distribution on immature and in vitro activated cells suggests that it may represent a receptor for signals related to cellular replication or differentiation.

Animals↗
PubMed1980

A semi-automatic device for pacemaker function analysis.

An external semi-automatic Pacemaker Function Analyzer (PFA) has been designed for routine examination (screening) of ambulatory-paced patients in general medical practice. The evaluation of the pacemaker (PM) function is based on recognition, decoding, and measurement of the occurrence of QRS complexes and pacing artifacts, and on logic processing of the decoded data. In this way, the state of the batteries and the integrity of the electronic circuitry and the electrodes can be determined. Other PFA applications concern supervision of hospitalized patients by interfacing the analyzer with the monitoring system of a Coronary Care Unit (CCU), transtelephone checking, and adaptation for use in specialized pacemaker clinics. The performance of the PFA was checked on 92 ambulatory patients. The PFA system recognized all but 0.29% of the QRS complexes and 0.21% of the pacing artifacts. Thirty-two of these patients were tested simultaneously by the PFA and the pacemaker clinic physician, both arriving at the same results. Twelve hospitalized patients were monitored in the CCU, after permanent PM implantation, for an average of 4 hours per patient. Although the PFA indicated 5% false-negative alarms for the hospitalized patients, it should be stressed that every true PM failure was promptly detected. It is anticipated that routine use of the PFA for management of paced patients will reduce the expenses incurred by frequent visits, as well as simplify the follow-up and surveillance of ambulatory and hospitalized patients, thereby facilitating the work of the medical staff.

Coronary Care Units↗
PubMed1977

Surveillance of pacemaker patients by an automatic pacemaker function analyzer.

An external, simply operated, fail-safe, automatic pacemaker function analyzer (PFA) has been designed for routine examination of ambulatory patients in local medical clinics and for continual surveillance of hospitalized patients in cardiology units. The instrument provides a comprehensive test of the pacing system, including the battery, pulse generator, and electrodes (leads), during varying heart activity. In the recorded ECG from 92 pacemaker patients, the PFA recognized all but 0.29% of the QRS complexes and 0.21% of the pacing artifacts; no signals were incorrectly attributed to the QRS complex. With the PFA, 1171 pacemaker tests were performed on these patients. In all cases, the PFA judged the performance of the tested pacemakers in accordance with the predetermined criteria. The PFA can be integrated into a pacemaker-patient surveillance system within a general-purpose cardiac care unit.

Electrocardiography↗
PubMed1977

Evaluation of electrocardiogram in emergency room as a decision-making tool.

The contribution of the electrocardiogram to the clinical judgment used by the physician in the emergency room to determine the necessity for hospitalizing patients was evaluated. Thirty-five percent of all 1,578 patients with presumed myocardial infarction referred to the Chaim Sheba Medical Center, Tel Hashomer, Israel, for a one-year period had subsequently diagnosed myocardial infarctions. The ECG in the emergency room detected only 65 percent of these. The physician's clinical judgment was impressive in his decision to admit to the hospital almost all of the remaining 35 percent, while not admitting very many of the patients who did not have subsequently diagnosed myocardial infarctions. When the myocardial infarction was not evident on the ECG and the abnormalities on the tracings were identical for patients with subsequent myocardial infarctions and those without, again the physician made the right choice more often than the wrong. The follow-up ECG also attested to the good judgment of the physician in the emergency room. Of the emergency room ECGs of patients without subsequent myocardial infarctions who were admitted to the hospital, 17 percent showed myocardial infarction by follow-up, while this happened to only 2 percent of those denied admission.

Decision Making↗
PubMed1976

Disposition of presumed coronary patients from an emergency room. A follow-up study.

All patients with presumed coronary problems seen at the Chaim Sheba Medical Center during a one-year period were followed up. The fate of those who were not hospitalized and the factors contributing to the two types of erroneous decisions, ie, refusing hospitalization to those needing it and unnecessary hospitalization of others, were evaluated. Approximately 50% of the patients were not admitted. Myocardial infarctions were later diagnosed in 6% of these patients. Another 8% were eventually categorized as other cardiac emergencies. Ten percent of all patients subsequently diagnosed as having myocardial infarctions were not admitted. On the other hand, 56% of the patients whose cases were later not considered to have been emergencies were hospitalized unnecessarily. Previous hospitalization for cardiac disease played a major role in making an error of both types. Other factors influencing the physician's decision regarding the patients' disposition included their age, sex, ethnic origin, and the findings from the emergency room electrocardiogram.

Adult↗